1. Field of the Invention
The present invention is in the field of building interior illumination using reflected sunlight through an opening in the roof (e.g., a skylight).
2. Description of the Related Art
Skylights provide natural sunlight to interior locations of a building that receive little or no light via windows. Although passive skylights are adequate in some situations, generally such skylights only provide sufficient lighting when the sun is at or near its zenith. During the winter months, the sun is so low in the southern sky (assuming the building is in the northern hemisphere) that the lighting provided by a skylight is not sufficient even when the sun is at its zenith.
Many mechanisms have been developed in response to the foregoing problem. For example, U.S. Pat. Nos. 5,999,323 (Wood), 6,433,932 (Aoki et al.), 6,493,145 (Aoki et al.), and 6,801,361 (Aoki et al.) illustrate a number of mechanisms for reflecting sunlight through a skylight to illuminate the interior of a building. The mechanisms include one or more mirrors positioned at an angle with respect to vertical so that when the sun is positioned low in the sky, the sunlight is reflected downward into the building. The mechanisms are motorized so that each mirror faces the sun and tracks the apparent movement of the sun across the sky. Thus, the light from the sun is reflected during the morning and the afternoon as well as during midday.
Although the known mechanisms provide advantages over passive skylights, the mechanisms include complicated structures and control mechanisms and thus tend to be unreliable and expensive to purchase, install and maintain. A need continues to exist for a room-mounted solar tracking device that is reliable and inexpensive and that is simple to install, and that requires little or no maintenance.